Flexible drive shaft coupling



June 3, 1941. c. F. HoTcHKlss, JR 2,243,960

FLEXIBLE DRIVE SHAFT COUPLIVNG Filed Feb. 4, 1958 Patented June 3, 1941UNITED Ys'mifss PATENT orifice FLEXIBLE DRIVE SHAFTACOUPLING Clarence F.Hotchkiss, Jr., Binghamton, N. Y.

Application` February 4, 1938, Serial No. 188,753

(Cl. (i4-4Jy Y 4 Claims.

|lihis invention relates to ilexible drive shafts and more particularlyto an improved coupling for drive shafts.

A primary object of this invention is the provision ofan improvedcoupling which forms a relatively small rigid portion of the driveshaftin order that the shaft may be guided around a relatively sharp angularcorner.

An additional object is the provision of a unitary coupling wherein aportion of the coupling ofthe outer covering sheath serves as a bearingfor the inner rotating drive shaft.

`Anadditional object is the provision of a coupling wherein the innerdrive shaft core may be displaced longitudinallywith respect to theouter sheath to permit an exceptional radius of curvature of the shaftadjacent thecoupling.

A still further specic object is the provision of an` improved couplingfor flexible drive shafts wherein there is provided, within the couplingitself, a recess permitting a longitudinal displacement of the innerdrive shaft core with respect to the outer covering sheathwhereby theshaft may ble accommodated to relatively sharp angular bends.

A still further objectis the provision of an improved couplingcomprising a. minimum of readily manufactured, easily assembled Y partswhich is durable iin construction, reliable in operation and-relativelysimple of assembly.

Other objects will in part be obvious and in part be pointed outhereinafter.

r'l'.he invention accordingly consists in the combinations of elements,`arrangements' of parts and features of construction all as will be morefully pointed out hereinafter and disclosed in the accompanying drawingwherein:

Figure l is a side sectional View of oneform of coupling embodying. theprinciples of this invention, and

`Figure 2 is a side sectional view of a modied form of coupling.

Having particular reference now to the modiflcation disclosed in Figure1 there is shown at I one segment` of aconventional flexible. driveshaft corerwhich, may be of any vdesired conventional construction `as ahelix of relatively fine wire. Shaft I0 is securedV in any desiredmanner as by soldering to a member II which is` comprised of steel orany other relatively hard metal.` Member II is provided atv itso-ppositeend, With a female threaded aperture I2 adapted to accommodate athreaded `male member I3 securedin any desired manner :toua fitting I4'which in turn is secured in a suitable manner to a section of a flexibledrive shaft core I5 corresponding to` core I0. Thus the connection ofthe interior or drive shaft core will be readily understood. Surroundingdrive shaft core ID is a `flexible sheath I6 which may be of rubber orsimilar resilient material provided with a lining. I'I. A similar sheathI8 having 'a lining I9 surrounds drive shaft core I5.

It will be understood that in a flexible drive shaft a plurali-ty of thecouplings comprising the instant invention may, if desired, be utilizedand the' distance between said couplings determi-ned by convenience, Itwill similarly be understood that at the opposite end of core I theremay be a coupling member similar to that described in connection withcore I5 and correspondingly at the opposite end o-f core I5 there mlaybe al coupling similar to that described in connection with core I0.

VSuitably secured to sheath IS in any desired manner is a rigid metallicmember 2U provided with an interiorly disposed annulus 2l. Annulus 2|serves as a guide for core I@ to maintain. the same centered withrespect to sheath Il. Member 20 is. preferably `con'lprised of brass orbronze or similar relatively soft metal and, adjacent the extremitythereof, is exteriorly threaded as indicated at 22. The interiordimension 'of member 2t is Vslightly greater than the exterior dimensionofY member II whereby when the parts are in assembled relation theinterior brass or bronze surface forms a bearing in which steel memberIIv rotates. Secured tosleeve I8; in any desired manner, is` a collarIIE-5v comprised: of any desired material and provided withl aninteriorly disposed annulus 2.5 which provides a. guide for thecentering of fitting I4 `and hence shaft I5. The. inner face 21 ofannulusy 28 forms an abutment for the extremity of member I-I. l Anexteriorly disposed annulus 28. carried fbycollar 25 serves to retain,in slidable relation an exteriorly disposed ring 3l] provided withthreads 3l adapted for engagement With threads 22` of member 20.

Thusfrom the foregoing it will be seen that in assembling the devicemember I3 is first threadedly engaged with recess I2Y which positionscollar 2i and member 20 in abutting relationship, ring 30 beingslidablewith respect to collar 25 in order that the same may be out of the wayduring such preliminary assembly. Ring 30 is., then moved towards member2i] and byV interengagement ofV threads 3|-` and 22 secured theretountil the abutment. of -annulus 28 with a shoul-der 32 carried by ring30 yprecludes fur-v ther .tightening thereof. Thus drive shafts I andI5, securely connected, are free to rotate within sleeves I6 and I8 andmember 2|] and collar 26 which, it will be seen, are comprised of aminimum of parts permitting a. relatively small lengthwise dimension ofthe coupling. Member 20 further serves as a bearing within which thecoupling of drive shaft cores I0 and I may rotate freely and withoutbinding Whereby the necessity for separate bearings and an additionalnumber of parts for the coupling is obviated.

Thus it will be seen that when the drive shafts AIt may here be pointedout the distance be- A- is therefor provided for the interior driveshaft tween the abutting extremity of member and annulus 2I issubstantially greaterthan the length of member I I and that sincermovement of member II is restricted by its abutment at one end withannulus 26 and at thej other with annulus 2| a substantial longitudinalmovement there-I of is permitted. Thus the inner drive shaftV core maymove longitudinally within the coupling with respect to the outer sheathwhen the parts are in related assembly to permit the accommodation ofthe component parts of the shaft to a relatively sharp radius ofcurvature without undue strain upon any of the associated mechanisms.

The construction shown in Figure 2 is similar to that shown in Figure 1in essentials but pirovides a bayonet coupling of the interior driveshaft core whereby the same may be rotated in either direction ratherthan in only one direction as is the case with the threadedly connectedinterior drive shaft of the type disclosed in Figure l.

In Figure 2 there is disclosed a flexible drive shaft core 5B similar todrive shaft core IIJ secured, in any desired manner, to an end member 5Iprovided with agroove 52 and an extending member 53 positioned forengagement with a corresponding groove 54 and extending member 55carried by amember 56 secured in any desired manner to a correspondingdrive shaft core 57. In assembly, grooves 52 and 54 are slida'blyengaged with extending portions 53 and 55 and a collar 60 which mayslide with respect to members V5I and 56 then slid over theinterengaging parts and secured in position as by means of a set screw6I which engages a flattened surface 62, which may be carried by eithermember 56 or 5I, but in the illustrative embodiment shown is carried bymember 55. Surrounding drive shaft 5I! is a collar 65 to which issecured, in any desired manner, a flexible sheath (not shown) similar tosheath I'I. Member 65 is preferably comprised of brass or bronze and isprovided with an interiorly relatively thick annulus 66 which providesabearing surfacek for the rotation of member 5I. A thinner and outwardlyextending flange 67 serves, by its abutment with an inwardly extendingflange 68, to retain a ring 69, threaded as at TED. A member 'IIsurrounds drive shaft core 51 and has secured thereto, in any desiredmanner, a flexible sheath (notshown) similar to sheath I3. Y Aninteriorly positioned annulus 'I2 serves as a guide for member 56.Member 'II may likewise be comprised of brass or bronze and is of adiameter slightly greater than the external diameter of collar 60whereby to provide a bearing surface for the same to permit readyrotation of the drive shaft within the coupling and obviate thenecessity for separate bearings. Member II is provided with a'threadedportion 'I3 for engagement with threads 10 of ring 50 and 51 areconnected in the manner previously described members 65 and 'II arepositioned in relatively tight relation and that ring 59 may be securedto member 'II by the threaded engagement of threads 'I0 and I3 to form arelatively tight connection.

In connection likewise with the modification it will be seen thelongitudinal motion of sleeve 60 is limited at one end by annulus 'i2and at the other by annulus 66. However, the distance between annulus 66and 'I2 is substantially greater than the length of sleeve 60 and alimited play core with respect .to the outer sheath.

. It will further be seen that in this modification of the inventionthere is also provided a coupling j comprised of a minimum of partswhich requires only asmall amount of space permitting a flexible driveshaft having one or more of such couplingsto be forced through a pipe ofsimilar device having a plurality of relatively sharp angular bendstherein. It will be seen that in this modification the necessity Vforseparate bearings in association with the mechanism is obviated, sincethe inner surface of members 65 and 'II serve the purpose of bearings inan emcient manner,

If desired it will, of course, be understood that a substantialclearance may be provided between the outer sheath coupling of eithermodification and the interior drive shaft core connecting members I Iand 60 whereby a substantially floating connection which permits radialas Well as longitudinal movement is provided. In such case the integralbearing construction which comprises one element of this invention iseliminated but the relative longitudinal movement of the core withrespect to the sheath is retained.

Thus it VVwill be seen that there are herein provided two modications ofthe inventive concept which accomplish all the objects of this inventionincluding many advantages of great practical utility especially withrespectrto simplicity of assembly, reliability of operation andYprovision of a coupling of relatively short length embodying a minimumof parts.

As many embodiments may be made of this inventive concept and as manymodifications may be made'of the embodiments herein-shown and describedit is to be understood that all matter hereinbefore set forth or` shownin the accompanying drawing is to be interpreted merely as illustrativeand not in ay limiting sense.

I claim as my invention:

1. In combination witha flexible drivel shaft including an outerVflexible sheath, a coupling comprising means for securing the adjacentends of said vinner shaft, and means for securing the adjacent ends ofsaid sheath, the last mentioned means comprising two sleeves eachattached to one of said ends one having an annulus and the other havingan exterior threaded portion and both of said sleeves having inwardlyextending means toIprovide an elongated open ended charnber throughvwhich said shaft passes and adapted to house securing means, and athreaded collar retained on the rst mentioned sleeve by the annulus andadapted to threadedly engagethe threaded portion of the last mentionedsleeve,

said means for securing adjacent ends of the inner shaft being carriedin assembled relation within said chamber and adapted for longitudinalmovement therein between said inwardly extending means. Y i

2. In combination with a flexible drive shaft including an innerflexible shaft and an outer flexible sheath, a coupling comprisingthreaded means for securing the adjacent ends of said inner shaft andmeans for securing the adjacent ends of said sheath, the last'mentionedmeans comprising two sleeves each attached to one of said ends, onehaving an annulus, and the other having an exterior threaded portion andboth of said sleeves having inwardly extending means to provide anelongated open ended chamber through which said shaft passes and adaptedto house securing means, and a threaded collar retained on the firstmentioned sleeve by the annulus and adapted to threadedly engage thethreaded portion of the last mentioned sleeve, the inner periphery ofsaid last mentioned sleeve forming a bearing surface in which saidthreaded means for securing adjacent ends of the inner shaft is adaptedto rotate, said threaded means being carried in assembled relationwithin said chamber and adapted for longitudinal movement therein andbetween said inwardly extending means.

3. In combination with a sectional drive shaft including a exible shaftand an outer, flexible sheath, a coupling comprising means for securingadjacent ends of said inner shaft including a cylindrical member, andmeans for securing the adjacent ends of said sheath, said meanscomprising two sleeves each secured to one of said ends, one of saidsleeves being provided with an annulus and the other with an exteriorthreaded portion and both of said sleeves having inwardly extendingmeans to provide an elongated openended chamber through which said shaftpasses and adapted to house securing means, and a threaded collarretained on the rst mentioned sleeve by the annulus and adapted tothreadedly engage the threaded portion of said other sleeve, the innerperiphery of said last mentioned sleeve forming a bearing surface inwhich said means for securing adjacent ends of the inner flexible shaftmay rotate, said means being carried in assembled relation within saidchamber and adapted lfor longitudinal movement therein between saidinwardly extending means.

4. In combination with a flexible drive shaft including an innerflexible shaft and an outer flexible sheath, a coupling comprising meansfor securing adjacent ends of said inner shaft and means for securingadjacent ends of said sheath, said rst mentioned means comprising amember attached to one end of said inner shaft and having a threadedaperture therein, and a unit `attached to the other end of said innershaft and having secured thereto a threaded member adapted to threadedlyengage said first member, said means for securing the adjacent ends ofthe outer flexible sheath comprising two sleeves each attached to one ofsaid ends one having an annulus and the other having an exteriorthreaded portion and 4both of said sleeves having inwardly extendingAmeans to provide an elongated open-ended chamber through which saidshaft passes and adapted to house securing means, and a threaded collarretained on said first mentioned sleeve by the annulus and adapted tothreadedly engage the threaded portion of said other sleeve, the innerperiphery of said last mentioned sleeve forming a bearing surface inwhich said means for securing adjacent ends of the inner flexible shaftmay rotate, said means being carried in assembled relation within saidchamber and adapted forllongitudinal movement therein between saidinwardly extending means.

CLARENCE F. HOTCHKISS, JR.

